Butler wore a pale blue button-up the same color as his striking eyes and a vintage baseball cap touting the Sturgis Motorcycle Rally, a subtle reminder of the film he was promoting. As we found a place to sit and made small talk, he listened like a devoted scene partner, holding eye contact and affirming things I said with a murmured “wow,” “yeah” or “interesting.”

He explained that this connected gaze, which he learned in an acting class, helped him conquer a once-crippling shyness. “If every time I feel attention on me, I start to feel like I’m imploding, then I just need to put my curiosity onto the other person,” he said. The people who’ve worked with Butler tend to mention that curiosity. They also describe him as “thoughtful” and “kind” as though they can hardly believe that a famous young actor would be either of those things. I mentioned that to him.

“Wow. Wow. Interesting,” he said.

Butler gives good brood but is not inherently brooding. He does not stumble out of nightclubs or refuse to leave his trailer in the morning. Though he lacks the whiff of danger that used to make bad-boy movie stars so alluring, that could be considered a good thing in our current, more cautious era. Eventually, danger curdles.

“I’ve seen every different way of being on a set,” said Butler, who grew up in Southern California and started acting as a teenager in shows for Nickelodeon and the Disney Channel. Still, his steadiness is not simply a reaction to bad behavior he’s witnessed; instead, it’s something more innate. “I owe a lot of it to my parents and the things that they instilled in me from being a child: Treat everybody how you want to be treated, regardless of if they can do something for you,” he said.

Butler’s father and grandfather were both motorcyclists, and he remembers sitting on the back of his dad’s bike as they went on long rides together. When he was 7, his parents divorced, and at 15, his father told him he was old enough to ride on his own. Still, it would have to be their secret: Butler’s mother forbade him from riding after his older sister got into a motorcycle accident that dislocated her shoulder.

Butler drew on all that and more to play Benny, whose loyalties to Kathy and to his motorcycle gang are often at odds. He also saw the part of himself that always has one foot out of the covers. As an actor, Butler is forced to be peripatetic, creating temporary but tight-knit circles in far-off places. “Then you finish the job and the family breaks up, and you go to another one,” he said. “In therapy one day, I realized that pattern reminds me so much of my parents’ divorce.”